Technical Field
The present disclosure relates to the field of adaptive optics. More particularly, the present disclosure relates to a deformable mirror and capacitive actuator array controller.
Background Discussion
Present-day adaptive optics are Micro-Electro-Mechanical (MEM) devices containing a mirror and an array of a multiple individual actuators that can each move particular points of the mirror's surface many, many times in a second—a thousand or more, so that these devices can modify their surface thousands of times in a second. Also called deformable mirrors, in the field of astronomy they correct distortion of wavefronts in starlight reaching Earth from millions of light years away that occurs as a result of contact with Earth's atmosphere in the last few miles of their earthward journey.
Adaptive optics and deformable mirrors may be among the most important developments in space imaging. The turbulence encountered by incoming light from space as it enters Earth's atmosphere can cause significant wavefront distortion, thus severely degrading received images. Deformable mirrors make it possible for ground-based telescopes to capture images of similar quality to those captured by space telescopes. These adjustments make it possible to view clearer, sharper images of very faint, very distant objects than is otherwise possible.
The surface of a deformable mirror can be modified to correct distortion in a sensed wavefront. The mirror does this by changing surface contours in real-time in response to wavefront distortion, detected by a wavefront sensor, by eliminating image imperfections resulting from the wavefront distortion. Removing these optical aberrations enables researchers to achieve extremely high-resolution images.
Thus, systems combining deformable mirrors, wavefront sensors and suitable control systems allow astronomers to enhance the quality of the received image by eliminating distortion in incoming wavefronts. The tiny, individual segments are carried on actuators that allow the segments to tilt and tip in milliseconds, allowing each segment many degrees of freedom, thus providing essentially seamless control of the wavefront image.